1 files changed, 49 insertions, 22 deletions

diff --git a/storage/xtradb/trx/trx0trx.cc b/storage/xtradb/trx/trx0trx.cc
index 30d4b7f6546..12f680bd7e2 100644
--- a/storage/xtradb/trx/trx0trx.cc
+++ b/storage/xtradb/trx/trx0trx.cc
@@ -53,6 +53,9 @@ Created 3/26/1996 Heikki Tuuri
 
 #include<set>
 
+extern "C"
+int thd_deadlock_victim_preference(const MYSQL_THD thd1, const MYSQL_THD thd2);
+
 /** Set of table_id */
 typedef std::set<table_id_t>	table_id_set;
 
@@ -1725,6 +1728,38 @@ trx_assign_read_view(
 	return(trx->read_view);
 }
 
+/********************************************************************//**
+Clones the read view from another transaction. All consistent reads within
+the receiver transaction will get the same read view as the donor transaction
+@return read view clone */
+UNIV_INTERN
+read_view_t*
+trx_clone_read_view(
+/*================*/
+	trx_t*	trx,		/*!< in: receiver transaction */
+	trx_t*	from_trx)	/*!< in: donor transaction */
+{
+	ut_ad(lock_mutex_own());
+	ut_ad(mutex_own(&trx_sys->mutex));
+	ut_ad(trx_mutex_own(from_trx));
+	ut_ad(trx->read_view == NULL);
+
+	if (from_trx->state != TRX_STATE_ACTIVE ||
+	    from_trx->read_view == NULL) {
+
+		return(NULL);
+	}
+
+	trx->read_view = read_view_clone(from_trx->read_view,
+					 trx->prebuilt_view);
+
+	read_view_add(trx->read_view);
+
+	trx->global_read_view = trx->read_view;
+
+	return(trx->read_view);
+}
+
 /****************************************************************//**
 Prepares a transaction for commit/rollback. */
 UNIV_INTERN
@@ -2071,7 +2106,7 @@ state_ok:
 
 	if (trx->undo_no != 0) {
 		newline = TRUE;
-		fprintf(f, ", undo log entries "TRX_ID_FMT, trx->undo_no);
+		fprintf(f, ", undo log entries " TRX_ID_FMT, trx->undo_no);
 	}
 
 	if (newline) {
@@ -2174,9 +2209,8 @@ trx_assert_started(
 #endif /* UNIV_DEBUG */
 
 /*******************************************************************//**
-Compares the "weight" (or size) of two transactions. Transactions that
-have edited non-transactional tables are considered heavier than ones
-that have not.
+Compares the "weight" (or size) of two transactions. The heavier the weight,
+the more reluctant we will be to choose the transaction as a deadlock victim.
 @return	TRUE if weight(a) >= weight(b) */
 UNIV_INTERN
 ibool
@@ -2185,26 +2219,19 @@ trx_weight_ge(
 	const trx_t*	a,	/*!< in: the first transaction to be compared */
 	const trx_t*	b)	/*!< in: the second transaction to be compared */
 {
-	ibool	a_notrans_edit;
-	ibool	b_notrans_edit;
-
-	/* If mysql_thd is NULL for a transaction we assume that it has
-	not edited non-transactional tables. */
-
-	a_notrans_edit = a->mysql_thd != NULL
-		&& thd_has_edited_nontrans_tables(a->mysql_thd);
-
-	b_notrans_edit = b->mysql_thd != NULL
-		&& thd_has_edited_nontrans_tables(b->mysql_thd);
-
-	if (a_notrans_edit != b_notrans_edit) {
+	int pref;
 
-		return(a_notrans_edit);
+	/* First ask the upper server layer if it has any preference for which
+	to prefer as a deadlock victim. */
+	pref= thd_deadlock_victim_preference(a->mysql_thd, b->mysql_thd);
+	if (pref < 0) {
+		return FALSE;
+	} else if (pref > 0) {
+		return TRUE;
 	}
 
-	/* Either both had edited non-transactional tables or both had
-	not, we fall back to comparing the number of altered/locked
-	rows. */
+	/* Upper server layer had no preference, we fall back to comparing the
+	number of altered/locked rows. */
 
 #if 0
 	fprintf(stderr,
@@ -2371,7 +2398,7 @@ trx_recover_for_mysql(
 			ut_print_timestamp(stderr);
 			fprintf(stderr,
 				"  InnoDB: Transaction contains changes"
-				" to "TRX_ID_FMT" rows\n",
+				" to " TRX_ID_FMT " rows\n",
 				trx->undo_no);
 
 			count++;